1. Field of the Invention
The present invention relates to a power supply device and an electric apparatus.
2. Description of the Related Art
An electric device that is used in a home, an office, or the like (e.g., a hair dryer, an electric water heater, or a microwave oven) is connected to a power source (e.g., a plug socket) disposed in a service space. The electric device operates by receiving electric power supply. For the home, the office, or the like (in which such an electric device is utilized), the maximum power amount is defined, which can be supplied from the power source. When power consumed by the electric device or the like exceeds a certain power amount, a circuit breaker cuts off the power, and thereby terminating the electric power supply. Accordingly, the above-described various electric devices are designed, in general, to operate within a range in which the power consumed by the electric devices does not exceed the maximum power amount, so that the plurality of electric devices can be used simultaneously.
Among electric devices, there are some electric devices that can more effectively demonstrate their functions, when the power supplied to each of the devices exceeds the maximum power amount of the power supply. For example, for the hair dryer, by using greater electric power, an air volume and temperature of blown-out warm air can be increased. For the electric water heater, also by using greater electric power, a time period for boiling water can be reduced.
As a method of supplying electric power to a load, a technique has been disclosed such that power output from a secondary battery (e.g., a lithium-ion battery) is added to power supplied from a power source, and the resultant power is applied to a load (cf. Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-191796), for example).